The present invention relates to a method for producing meal containing mannose as the feedstuff additive, which is effective for preventing infection caused by bacteria, especially by Salmonella.
Addition of mannose to feedstuff has conventionally and expectantly been known to have the effect of excreting Salmonella from animals fed with the feefstuff (Poultly Science 1989 68 1357). It has also been known that Arecaceae plant-derived meals such as copra meal or palm kernel meal etc. abundantly contain mannan and the followings are disclosed. To produce mannoses including mannose by having an enzyme function to mannan solution obtained from such as copra meal (residue remaining after Arecaceae oil extraction), E. melanococca GAERTN called Corozo, Phytelephas macrocarpa, and the like (Japanese Laid-Open Patent Application No.1988-49093). To use substance in order to improve the taste of feedstuff, which substance is obtained by enzymic decomposition of palm kernel meal etc. for oligosaccharide production (PCT/GB94/02802). To produce mannose or mannose polisaccharides through hydrolytic reaction caused by having an enzyme (solution) function to the materials including galactomannans such as copra meal, after which the reactive solution is extracted and dried by such as spray-drying (Japanese Laid-Open Patent Application No.1995-236429, Japanese Laid-Open Patent Application No.1996-173055).
These methods, however, have problem in the extraction efficiency for mannose. Using a large amount of water leads to high efficiency, while it costs a lot for drying.
It, therefore, tends to be believed that when the reactant, which is directly dried after the enzymic reaction without any extraction process, is used for feedstuff or feedstuff additives, only a small amount of water used for the reaction is to be deleted, which displays good economical performance without any loss of mannose during the extraction. Such ideas have actually been filed for patent applications (Domestic Re-Publication of PCT International Publication (for Patent Application) No.99-08544, etc.), but are extremely difficult to carrying it out. Post-reaction meal contains considerably high level of monosaccharides, so that it becomes sticky as water evaporates in the process of drying. It causes considerable adhesion to the inner wall of the dryer, which makes the continual operation difficult and leads to decrease in the producing ratio. In addition, mannose is heat-decomposed due to the long drying period, so that the mannose finally obtained is far below the expectations. The inventors thus have begun to look from the different viewpoint and sought for a method using the post-reaction meal without drying, and they have filed the application for method wherein the post-reaction meal is mixed with dried powder particle and then water in the post-reaction meal is diffused over the dried powder particle (Japanese Laid-Open Patent Application No.2000-245357). But the problems have not totally been resolved since there arise other problems such as growth of mold caused by uneven mixing, rise in the cost of storage and distribution resulting from increase in the volume of feedstuff, and the like.
As mentioned above, problems lie in the drying process for obtaining meal containing mannose that the production ratio is low or that the manufacturing cost is expensive, which is reflected in the high cost of products. Therefore, when the sufficient level of meal containing mannose, which is the level substantially effective for the prevention of Salmonella, is added to feedstuff, the price will exceed the adequate price in the poultry market.
Taken the situations together, the market requires a method to provide mannose as the feedstuff additive at lower price.
The present inventors and others have made keen studies to solve the problems mentioned above. And they have found that by mixing and drying copra meal or palm kernel meal, which does not react to the wet composition obtained by having a mannnan degrading enzyme function to Arecaceae plant-derived meals such as copra meal or palm kernel meal, feedstuff containing mannose can be effectively produced. Here the present invention has completed. The invention, therefore, focuses on a method for producing mannose-containing feedstuff, wherein powder particles containing cellulose and/or hemicellulose is mixed with the wet composition obtained by having a mannnan degrading enzyme function to Arecaceae plant-derived meals such as copra meal or palm kernel meal, followed by the drying process.